Post-PSLE Activity: Watch a video on Periodic Table

In 1864, Dimitri Mendeleev published the first periodic table that organized all the known elements in the world. This tool was groundbreaking for many reasons–including the fact that Mendeleev planned with incredible foresight, leaving space for any new elements that would be discovered beyond his time.  

Go to the following website which has an interactive periodic table. Click on each element to watch a video and find out more about the element.

http://ed.ted.com/periodic-videos

Educational Science Videos - Wild Kratts Series

This animated series introduces kiddos to a variety of wild animals and teaches them Science concepts such as animal behaviour, habitats and adaptations. Kids who like humour and adventure will love to watch this series. Suitable for children between 4 years old and 8 years old.

As the videos often mention threats to animal habitats, parents can also follow up by engaging their kiddos in discussions on current environmental issues and conservation.

http://www.amazon.com/Wild-Kratts-Creature-Adventures/dp/B004NIX05W

Symbiotic relationships

Symbiotic relationship occurs when at least two organisms live together in a way that benefits at least one of the organisms. Mutualism is an example of a symbiotic relationship whereby both organisms benefit each other.

One example of mutualism is the relationship between the honeyguide bird and the honey badger or ratel. The honeyguide bird leads the badger to honey (benefit to badger) while the badger tears apart the hive (benefit to the bird as it can now access the honey). Watch the video below on this symbiotic relationship.

Differences between a slug and a snail

Today, I showed my toddler a snail while we were taking a walk in the estate. An eight-year-old child passed by and was excited to see the snail too. I overheard the child's mother asking, "Do you know what is the difference between a snail and a slug?"

I thought it would be interesting to write a short post on this. The main difference between a snail and a slug is that a snail has a shell while a slug does not.

Other features are the same for snails and slugs:
- they move around on a flat, muscular foot.
- they have one or two pairs of tentacles on their heads. The larger pair of tentacles usually has eyes at the end.
- they eat using a tongue-like organ called a radula, covered with rows of teeth.
- most of them have both male and female reproductive organs and hence are hermaphrodites.

Slug

Snail

Differences between an ape and a monkey

I took my toddler to the Singapore Zoo recently and overheard a child asking his mother, "Mum, what is the difference between an ape and a monkey?" This is a commonly asked question. Here's a brief answer:

The main difference between an ape and a monkey is that an ape does not have a tail while a monkey has a tail.

There are other differences between an ape an a monkey. They are:
(1) An ape is generally larger than a monkey.
(2) An ape has a longer lifespan than a monkey.
(3) An ape has a larger brain-to-body size ratio.
(4) An ape has higher intelligence.

Of course, there are exceptions. Some monkeys do not have tails and some are large. Gibbons, considered to be lesser apes, are smaller than some monkeys.

Great Apes
Gorillas, Chimpanzees, Bonobos and Orang utans

Lesser Apes
Siamangs and Gibbons

Monkeys

Baboons, macaques, tamarins etc

You can find out more by reading these books:
Apes and Monkeys by Barbara Taylor
All about Monkeys and Apes by Jordyn Madison

Here are some pictures of apes and monkeys:

TAMARIN

Gorilla

ORang Utan with babY

Chimpanzee

Gibbon

Insect-pollinated flowers

The P5 kiddos are learning about pollination and fertilisation during our P5 Science classes. The kiddos have learnt that insect-pollinated flowers usually have large petals, bright colours, sweet nectar and nice scent. Here are a few images of insect-pollinated flowers:

A Peek into our Science Lessons...

Our P4 classes are learning concepts on Heat while our P5 classes are learning concepts on Electricity. Take a peek into some of our hands-on activities during the lessons. We believe that these hands-on activities will help the children develop Science process skills and understand the Science concepts better.

Do all sharks need to keep moving to stay alive?

Yesterday, one of my P6 pupils shared with the class that he had read in a National Geographic Magazine that sharks need to keep moving to stay alive.

Do all sharks need to keep moving to stay alive? It depends on the breathing technique the sharks use. Ancient shark species do not have to constantly swim to breathe as they pump water through their mouth and over their gills. This method is known as buccal pumping. The sharks use their buccal, or cheek, muscles to pull the water into the mouth and over the gills. Examples of shark species that use this method of breathing are nurse sharks, angel sharks and carpet sharks. Most of these species have a more prominent spiracle, which is a tube behind the eyes. When a shark is at the bottom of the ocean floor and cannot breathe through its mouth, the spiracle acts like a mouth by pulling in water.

Over time, sharks evolved and the modern shark species use a method known as ram ventilation. By swimming fast, these sharks actively force water into their mouths for processing. Shark species that breathe using ram ventilation do use buccal pumping to breathe when they are idling.

There is a category of sharks known as obligate ram ventilators that are said to have to swim constantly to stay alive. Only about two dozen of the 400 identified shark species fall in this category. One such species is the great white shark.

Video on Pollination

An informative video on pollination of flowers. It covers how:
- pollination by insects
- pollination by wind
- perfect flowers (flowers with male and female parts)]
- imperfect flowers (flowers with male or female parts only)

Informative Video on DNA and genes

Found an informative clip that explains what DNA and genes are. It is clear and easy to understand. Good for kids who want to learn beyond the Science syllabus! Highly recommended.

DNA and chromosomes

The P5 kiddos in my P5 Science classes have just completed the topic on Cells during the school holidays.
I have shared with them some information on DNA and chromosomes that is beyond the syllabus.

(1) What is DNA?
DNA stands for deoxyribonucleic acid. It is found primarily in the nucleus of cells. It is the material that transfers genetic characteristics from one generation to another in living organisms.

A DNA molecule is made up of a series of nucleotides arranged in 2 strands that resemble a ladder and twist to form a double helix.

Nucleotides are made up of a base, a sugar and phosphate. The 4 bases are adenine (A), guanine (G), cytosine (C) and thymine (T). The 4 bases pair with each other (A with T and G with C). How they are
ordered or sequenced provides information needed for the growth and development of our bodies.

(2) What are chromosomes?
It is a structure within the cell nucleus. It is made up of a single coiled piece of DNA. Human cells have 23 pairs of chromosomes. 23 chromosomes come from our mother while 23 chromosomes come from our father.

(3) Sex chromosomes determine our gender
What sex / gender a baby will be is decided when the egg and sperm unite. Each egg and each sperm have one sex chromosome.

There are two kinds of sex chromosomes - X and Y. Eggs carry only an X and sperm carry either an X or a Y

X+X means the cell will develop into a baby girl.
X+Y means that it will develop into a boy.

Image: How sex chromosomes determine our gender

Animated Interactive Clip on Digestion (Lower Block Science)

Found an informative animated clip on digestion. The clip contains some information that is beyond the syllabus.

There is also a transcript on the clip on the webpage. Check this weblink:
http://www.sciencelearn.org.nz/Contexts/Digestion-Chemistry/Sci-Media/Animations-and-Interactives/Digestion-of-food

What determines the gender of a baby sea turtle?

 

A baby sea turtle is known as a hatchling. After an adult female sea turtle nests or has laid her eggs, she returns to the sea, leaving her eggs to develop on their own. The developing hatchlings do not have sex chromosomes. Their gender is determined by the temperature of the sand they are found in.

There is a "pivotal" temperature which varies slightly among species, ranging between 28 and 29 degrees Celsius. If the temperature of the sand is above this temperature range, female turtles will result. If the sand is below this temperature range, male turtles will result.

~ Serena's Greenhouse

Adaptations - Puffer fish

Watch this video to find out how a puffer fish protects itself from its predators...

Adaptations
When threatened by a predator, a puffer fish will suck in water and sometimes air to inflate itself like a balloon, making itself look bigger. Hence the predator will not be able to eat it as it is too big for the predator's mouth. Some species also have spines on their skin to ward off predators.


If a predator gobbles up a puffer before it inflates, it will not enjoy the food. Most pufferfish contain a toxic substance that makes them taste foul and potentially deadly to other fish. There is enough toxins in one pufferfish to kill 30 adult humans and there is no known antidote.


Other facts about the puffer fish
In Japan, puffer fish are known as fugu and they are an expensive delicacy. They are prepared only by licensed fugu chefs.

Seahorse reproduction

Is a seahorse a mammal or a fish? How does a seahorse reproduce?


The seahorse is a fish. Unlike most fish, it does not have scales. It has rectangular bony plates that cover its body. Seahorses do not have teeth and swallow their food whole with powerful suction through their snout. To hide from their predators, they grow long skin appendages so that they can blend in better among the algae and seaweeds.


Seahorse reproduction is unusual as the male is the one that becomes pregnant. During mating, the male and the female entwine their tails and the female connects a tube called an ovipositor to the male's pouch. After the eggs are moved into the male's pouch, the male will fertilise them. The fertilised eggs will hatch in the male's pouch.


The males are pregnant for several weeks before giving birth. When they prepare to give birth, the males undergo muscular contortions that last for about ten minutes. They will bend forward and backward. Then the brood leaves the male's pouch, one after another.




Watch this video that shows the male seahorse giving birth...

Watch another video that is downloaded from the Internet...

Cool Science Gadget: Hand Boiler

During a Science lesson, one of my lovely pupils, Theresa, brought along a hand boiler. The class was excited. They found it cool.

Steps:

1. Hold the bottom bulb of the hand boiler in your hands and squeeze it.


2. Observe what happens.

Observation:

When you hold the bottom bulb of the hand boiler in your hands and squeeze it, you will see the liquid bubbling and it will go up to the top bulb.

Watch a video...

Challenge:

How do you get the liquid back to the bottom bulb of the boiler without turning it over?

Solution:

Hold the top bulb in your hands Or

Wait for the air in the bottom bulb to cool off

How does the hand boiler work?

Teacher Serena's Explanation:

The liquid in the hand boiler has a low boiling point. When we hold the bottom bulb in our hands, heat from our hands is transferred to the bulb and to the liquid and vapour above it. The vapour that sits above the liquid gains heat and expands. This additional warmth causes more liquid to evaporate.

This Science toy demonstrates the relationship between temperature and pressure. The hand boiler is a closed container. Therefore, as temperature goes up, the molecules of gas in the container move faster and this causes pressure to increase. As the pressure increases in the lower bulb, the liquid will be pushed up the tube into the top bulb. When the level of the liquid in the bottom tube falls below the end of the tube, vapour can travel up the tube and rise through the liquid, giving the appearance of boiling.

Conversely, as the air in one of the chambers cools off, the molecules of gas slow down, lowering the pressure. The liquid will move from an area of high pressure to an area of lower pressure.

~ Serena's Greenhouse

Science Misconceptions on States of Water

When we boil water, we see "white clouds" coming out of the spout of the kettle. What are the white clouds?

Misconception:
The "white clouds" are steam.

Correct concept:
The "white clouds" are condensed water droplets. They are formed when the steam meets the cooler air in the surroundings, lose heat and condense to form water droplets.
The "white clouds" are not steam. Steam is in the gaseous state and cannot be seen.

~ Serena's Greenhouse

Science Misconceptions on Respiration

Misconception (1):
Breathing is the same as respiration.

Right concept: 
Breathing is the exchange of gases between the air and our bodies. On the other hand, respiration is the process by which oxygen is used to break down food to provide our body with energy.

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Misconception (2):
Plants carry out respiration only at night.

Right concept: 

Plants carry out respiration all the time, even when they are photosynthesising.

~ Serena's Greenhouse

Science Misconceptions

Is breathing the same as respiration? Can we use the terms "respire" and "breathe" interchangeably?

Children have certain misconceptions about Science. As educators and parents, it is useful to know these misconceptions so that we can lead the kids in the discussion on these misconceptions. We can also gear our lessons or discussions towards clarifying these misconceptions.

I will be sharing some of these common misconceptions in this blog. You may want to test them out on your kid and see if he or she has these misconceptions too.

Recommended Reading List for Science

In the PSLE, there are some questions (Physical and Life Sciences) that will require pupils to apply Science concepts to everyday situations or phenomena around them. Parents and pupils have often approached me to recommend them some useful reading materials for Science. Pupils are encouraged to read widely so that they are more aware of how Science concepts are applied in everyday situations or certain gadgets, for example, bimetallic strips used in thermostat (popular question related to the P4 Topic on Heat in Top School Examination Papers).

Here are some books or magazines that pupils could read:
- My Pals Are Here Sciene PSLE Revision Guide
- My Pals Are Here Science Booster
- Talking Science Magazines
- Young Scientist Magazines
- Non-fiction books from the National Library Board on adaptations, symbiosis, etc

For younger kids, encourage them to read the Magic Schoolbus series to find out more about themselves and the world around them.
http://www.scholastic.com/magicschoolbus/books/index.htm

~ Serena's Greenhouse